Worcester 28Si ii No Heating from Timer but Hot Water ok All aspects of plumbing questions and answers, help, tips and information

[Casey744]

Hi,

We moved into a house in July and due to having to do work on it, yesterday was the first time the boiler has been turned on.

I removed the wired thermostat. The way it was wired was using a 3 core and earth wire with the neutral going to N, Live going to L, a link wire between L and LS, a link wire between N and Ns and the third wire going to Lr.

I wanted to install the regular digital programmer for the boiler so I removed the 3 core and links and put a regular cable in wiring the Live to L, neutral to N and adding the link back between Ls and Lr as stated in the manual and plugged the digital clock into ST5 on the PCB.

The hot water fires up the boiler with no problem, but absolutely nothing happens when the CH is timed to come on. I have put a mechanical clock on too and still the same happens.

Can anyone tell me where I have gone wrong or what else to do/check?

[Casey744]

Update - I took everything out of the PCB re-connected it all and the CH now kicks in when there is a demand. However, it ignites, makes some noises for 30 secs and then gives up.

If you then turn the hot water on, the boiler bursts into life as normal. When it's turned off, if there is still demand for the CH it tries again only to give up again 30 secs later.

No hot water seems to be leaving the CH flow pipe as it stays cold. Could the issue be with the pump? Although if the hot water works fine, wouldn't that mean that the pump works?

No flashing lights on the reset switch and reset switch has been pressed but the same thing keeps happening